Refactor snapshot module into subcommands.

cmd/snapshot_create.go

@@ -0,0 +1,79 @@
+package cmd
+
+import (
+	"fmt"
+	"github.com/gonuts/commander"
+	"github.com/gonuts/flag"
+	"github.com/smira/aptly/debian"
+)
+
+func aptlySnapshotCreate(cmd *commander.Command, args []string) error {
+	var (
+		err      error
+		snapshot *debian.Snapshot
+	)
+
+	if len(args) == 4 && args[1] == "from" && args[2] == "mirror" {
+		// aptly snapshot create snap from mirror mirror
+		repoName, snapshotName := args[3], args[0]
+
+		repoCollection := debian.NewRemoteRepoCollection(context.database)
+		repo, err := repoCollection.ByName(repoName)
+		if err != nil {
+			return fmt.Errorf("unable to create snapshot: %s", err)
+		}
+
+		err = repoCollection.LoadComplete(repo)
+		if err != nil {
+			return fmt.Errorf("unable to create snapshot: %s", err)
+		}
+
+		snapshot, err = debian.NewSnapshotFromRepository(snapshotName, repo)
+		if err != nil {
+			return fmt.Errorf("unable to create snapshot: %s", err)
+		}
+	} else if len(args) == 2 && args[1] == "empty" {
+		// aptly snapshot create snap empty
+		snapshotName := args[0]
+
+		packageList := debian.NewPackageList()
+
+		snapshot = debian.NewSnapshotFromPackageList(snapshotName, nil, packageList, "Created as empty")
+	} else {
+		cmd.Usage()
+		return err
+	}
+
+	snapshotCollection := debian.NewSnapshotCollection(context.database)
+
+	err = snapshotCollection.Add(snapshot)
+	if err != nil {
+		return fmt.Errorf("unable to add snapshot: %s", err)
+	}
+
+	fmt.Printf("\nSnapshot %s successfully created.\nYou can run 'aptly publish snapshot %s' to publish snapshot as Debian repository.\n", snapshot.Name, snapshot.Name)
+
+	return err
+}
+
+func makeCmdSnapshotCreate() *commander.Command {
+	cmd := &commander.Command{
+		Run:       aptlySnapshotCreate,
+		UsageLine: "create <name> from mirror <mirror-name> | create <name> empty",
+		Short:     "creates immutable snapshot of mirror contents",
+		Long: `
+Command create .. from mirror makes persistent immutable snapshot of remote repository mirror. Snapshot could be
+published or further modified using merge, pull and other aptly features.
+
+Command create .. empty creates empty snapshot that could be used as a basis for snapshot pull operations, for example.
+As snapshots are immutable, creating one empty snapshot should be enough.
+
+ex.
+  $ aptly snapshot create wheezy-main-today from mirror wheezy-main
+`,
+		Flag: *flag.NewFlagSet("aptly-snapshot-create", flag.ExitOnError),
+	}
+
+	return cmd
+
+}